Valid point, but we have to have the capability for the high end fight, I don't think to the level we structure our forces now but keeping xxx % in high end capes unlikely to be used but necessary for deterrence and if the SHTF, to win the fight.
There's no reason we should have to spend 500k+ per PGM delivered to a target in a permissive air environment, buy the right systems in numbers to make mowing the grass economical but never doubt shit does happen sometimes. Look at 1982 when Argentina invaded the Falklands, 1990 when Iraq invaded Kuwait, etc... or any other smaller unconventional conflicts that could have escalated further, you get a patron backing a rouge nation, like Russia, and suddenly you find you might need capes you thought you wouldn't in certain AORs, the deployment of Russian S-400s / S-30s in Western Syria being a prime example. They probably won't target or threaten us but what if they do and tell us not to fly in x airspace or else? We have to be able to tell them to pound sand and we'll do what we want, where we want, when we want and that's that. Not advocating warmongering or being a global a-hole but be able to follow thru and let that be common knowledge around the world.
Look at the Iranians and their new toys, S-300s from Mother Russia.
https://rusi.org/publication/rusi-defence-systems/why-iranian-purchase-s-300-should-worry-gulf-states
When the Falklands were invaded, PM Thatcher was meeting with her cabinet, one of them said "if we do nothing, we will wake up in another kind of country." Meaning if people know they can push you around either by you not wanting to fight or not able to fight, they will push you around. Do you think Iran would wait 6.9 seconds if they thought they could close the air / sea in choke points like the Strait of Hormuz if they knew the US could not or would not operate there if we didn't have the capes to prove them wrong?